This invention relates to inertial acceleration sensors and in particular to pendulous integrated gyroscopic accelerometers.
Accelerometers provide a measure of acceleration with respect to an inertial reference. A pendulous integrating gyroscopic accelerometer utilizes a floated gyroscope with an inherent mass unbalance with respect to a support axis. When an acceleration is imposed with respect to the sensing axis of the instrument, the floated gyroscope or float assembly is deflected by an angle, which is sensed by a pick-off. Typical prior art devices utilize a magnetic suspension for the float assembly supporting mechanism or suspension. These magnetic devices provide the required low angular spring rate and high radial and axial spring rates. These magnetic suspensions suffer from the requirement for exacting mechanical tolerances and costly manufacturing processes. There exists a need for a simpler and less costly device to improve the reliability and manufacturability of the pendulous integrating gyroscopic accelerometer float assembly suspension.
This invention provides flexure assembly for suspending a gyroscopic float assembly in a floating gyroscope system. The flexure comprises an outer rim and a plurality of flexure beams connected to the outer rim. A pair of such flexures is used to support the gyroscopic float assembly.
Each of the flexures may have in inner hub with the corresponding flexure beams having inner ends connected to the hub and outer ends connected to the outer rim.
The invention may include a plurality of flexure tabs extending outward from outer perimeter portions of the rims for mounting the flexure assembly to a pair of end caps.
The flexure preferably further comprising a plurality of strain relief passages formed in the rims and arranged to provide relief from thermally induced stresses.
The flexure preferably also further comprising a plurality of angular stops formed in inner perimeter portions of the rim and arranged to constrain the flexure against rotation about a selected axis.